This paper presents a new semantics for contrastive topic (CT) constructions that relies on a topic abstraction operator to generate nested alternative structures. Compared to previous accounts like Büring 2003, the proposal is conservative in that it neither appeals to a new type of F-marking, nor stipulates any discourse conditions particular to the CT construction. Rather, Rooth's squiggle (~) operator is used to relate the focus alternatives of a CT-containing utterance directly to a complex question antecedent. Beyond the advantage of parsimony, the account has several empirical advantages. It extends easily to CT questions and new multiple CT data, both of which are problematic in the standard approach. The proposal also gives an explanation for the limited island sensitivity of English CT, and correctly predicts narrow scope for CT-marked quantifiers like few.